So-called hip spirit levels consist of a base body or a guiding member with two limbs or nibs pivotably movable therein, in which there are integrated, in each case, a spirit level or bubble tube. For determining the body posture the person to be measured must place himself upright in his natural posture. The person carrying out the diagnosis then from the rear holds the hip spirit level at the height of the hip onto the body. The pivotable limbs at the same time are placed on the hipbone on both sides. By way of the deviation of the bubble tube of the spirit level from the horizontal one may diagnose whether and to what extent the patient maintains the pelvis in an oblique presentation. Generally this oblique presentation is described as leg shortening, wherein this indeed is present in the form of a shorter leg or more often only appears to be, generally caused by an over-stretching of muscles or ligaments. The cause of such an apparent leg shortening may be a knock or a short incorrect loading of the musculoskeletal system.
A hip spirit level for determining the leg shortening according to the above described state of the art is known from CH-A-671 '330.
The hip spirit level according to the state of the art has several disadvantages. The body, by way of the displacement of the pelvis, compensates for the oblique presentation. The hip spirit level therefore measures the oblique presentation, which has already been partly compensated, but not the effective incorrect loading of the pelvis and of the legs.
Furthermore, the patient in this situation rarely positions himself in his natural posture, so that the readings are not true. Furthermore the position of the hip bone may not be easily determined particularly with obese persons, so that the measurement often may not be carried out with due care and attention.
For this reason several measuring devices are known which directly determine the incorrect loading of the legs in which the patient in each case with one foot places himself on a measuring balance.
FR-A-2,491,754 describes such a device for determining leg shortening. The patient places each foot on a vertically movable plate, wherein from the front, abutment elements are pressed onto his knee and his pelvis. The different weight loading of the two plates is registered and the plates are mutually lifted or lowered until they register the same weight loading. The difference in height of the two plates then indicates the shortening of the leg.
U.S. Pat. No. 5,088,504 discloses a measuring device with which pelvis displacement and weight loading for each leg may be ascertained. The measuring device comprises a base and a vertical trunnion attached thereon. In the base are arranged two balances, which are provided with an abutment for the heels of the patient. A measuring element for determining the pelvis displacement is displaceably arranged on a vertical trunnion, wherein the measuring element comprises a vertical displacement rod for setting the height, and two horizontally displaceable abutment bars for measuring the pelvis. For measurements, the patient freely places himself on the base with his back to the vertical trunnion.
In U.S. Pat. No. 4,033,329 there is described a similar measuring device where, however, there is no positioning abutment for the heels. A reliable reproduction of the measurement is not possible with the lack of a reference point.
WO-A-95/35063 shows a measuring device with two balances and a vertical trunnion on which there are arranged two measuring and fixation elements, one for the pelvis and one for the shoulders. For measurement, the patient stands with his face to the vertical trunnion, with the balances having elements for positioning the heels.
From AT-U-002,239 there is known a measuring device for determining an incorrect loading of the human body which comprises a base element having two balances and an adjustment unit for positioning individual body points, or regions, of the person to be measured. The adjustment unit comprises a vertical trunnion arranged on the base element, on which trunnion fixation elements are arranged in a vertically displaceable manner, wherein a first fixation element is present for the fixation of the hips and a second fixation element is present for the fixation of the upper body. On the base element there is present an abutment for positioning the heels of the person to be measured. The balances may be calibrated absolutely with respect to a calibration value or relative to one another. Furthermore, a third fixation element is present for the fixation of the knee as well as a lateral abutment for the sides of the foot. The abutment for positioning the heels is arranged on the side which is proximal to the vertical trunnion, wherein the vertical trunnion forms a positioning axis for defining a middle body line of the person to be measured.
All these measuring devices have the disadvantage that the measurements yield insufficient data for an exact diagnosis, since with the more simple apparatus one does not take into account the posture of the whole body, and with the more advanced apparatus the deviations of the body posture are reduced to a two-dimensional pattern. Because of this, incorrect postures and shortenings may not be unambiguously detected since twisting or distortions are not taken into account. For example, a distortion of the pelvis leads to an incorrect posture of the ilium and of the femur. Since the previously known apparatus only detect two-dimensional deviations within the frontal plane, such a distortion incorrect posture would be diagnosed as a shortening or lengthening of the femur, although there is not present any length change of the femur. In the same manner this applies to distortion of the shoulder girdle.
The insufficient, two-dimensional base of data for diagnosis thus does not permit the necessary therapeutic measures to be correctly planned and carried out.